Process for manufacturing multilayer film circuits



PROGESS POR MANUFAGTURING MULTLAYER FILM GIRCUITS Filed Jan 20 1964 Jan. 30, 1968 P. PR|TCHARD, R ETAL 2 sheetS-Sheet 2 netal iilm having apertures where electrical contact is desired between the iirst metal mm and a Subsequently dep0sited metal lm,

dep0siting a Second metal mm having a relatively 10W Critical current level at the Selected operating tem erature Over the iirst polymer insulating iilm Such that the second Inetal film contacts the iirst Inetal lnT plane Where exp0sed through the flrst p0lyfrler insulating layer,

applying a third coat Of phot0resist 0Ver the first 130lymer insulating mm and the Second metal mm substrate, exp0sing the third coat of phot0-Tesist in predetermined areas, and developing the third coat of ph0t0resist to Temove the phot0-Tesist in 13Tedeter Tnined areas and thereby leave the Second Ineta1 lIn unpr0tected in Said predetermined areas,

imnTeTsing the Substrate in a Selective etchant lid to remove only the predetermined areas exp0sed through th6 third coat of ph0t0-resist,

relnoving the renlaining poftions of the third coat of )hotOresist by a Stripping solution,

applying a fourph coat Of photo-Tesist over the second metal mm and the HTSt polymer insulating mm, ex- )()Sing the fourth C0at of phot0resist in predeter- Tnined areas, and developing the fourth coat of ph0t0resist to form a Second polymer insulating layer over he Second metal film and the rst polymer insulating mm having apertures Where electrical contact is desired between the second netal filn and a Subsequently dep08ited metal iln1,

depositing a t,hird metal mm Over the second 01ymer insulating mm such that the third metal mm extends through any openings in the second polymer insulating layer into electrica1 contact with the second metal mm exposed therethrough, the third Inetal lm having a felatively high critical current level at the Selected operating temperature,

applying a fifth coat 0f )hOt0TeSiSt over the third metal mm, exposing redeteTmined areas of the fth `coat of phot0resist, and deve10ping the ifth coat Of ph0t0resist to remove the phot0resist in predetenmined areas and leave the third metal filn1 un protected in said predetermined areas, and

itnTnersing the substrate in a Selective etchant i llid to reInove the unpr0tected portions of the third 1Tletal mm.

6- In a process for manufactuling multilayer mm circuits, the Seqtlential Ste1)s of:

depositing a metal mm on a Surfa ce of a Substrate, applying a coat 0f positive phot0-1esist ()vel' the n1etal mm, exposing the coat of positive ph0t0resist in 1)Tedetermined areas where the metal lm iS t0 be Temoved, deve10ping the c0at of 0sitive ph0to-Tesist t0 remove the phot0resist in Dhe redetermined areas and leave the redetelmined areas of the metal mm unprotected, Sllbjecting the Substrate to a selective etchant uid to remove the metal mm in the unpr0tected areas, exp0sing the coat of p0sitive phot0-Tesist a second tiIne in Second predeterrnined areas 'Where electrical conta,ct between the rSt metal mm and a metal lm Subsequent1y t0 be dep0sited is desired,

developing the )hOt0SenSitiVe nlateria1 t() remove the phot0resist in the Second redetermined areas, and

Xing the renaining phot0sensitive Inaterial to there after prevent itS ren10val after subsequent exposufe and deve10pment whereby the xed hOtOSenSitiVe material Will Serve as an insulating layer between said rSt metal mm and Said metal mm Subsequently to be dep0sited UNTED STATES PATENTS Z 711,983 6/19 Hoyt. Z,966,647 12/ 1960 Lentz 338`32 3,059,196 10/196Z Lentz 3383Z 3 1 1S,423 12/ 1963 Ashworth. 3 21-9 749 11/196 shuster et al 133 FOREGN PATENTS 240 Z48 9/1962 Australia.

l,34j,l63 10/1963 France OTHER REFERENCES Method of Producing Three DInenSiOnal Printed Circuits, I(lippel IBM Disc10sure Bulletin, V01. 2 No. 4 December 19S9 7 and 8. 

